Multiband fixed frequency calibration panoramic radio receiver



M. WALLACE ET AL 2,465,500 MULTIBAND FIXED FREQUENCY GALIBRAIIONA March 29, l1949.

PANORAMIC RADIO RECEIVER 2 Sheets-Sheet 1 Original Filed July 17, 1941 wUKDOm l IM lwlzlL/m H wlmdnmm@ l MARCEL WALLACE HORACE G. MILLER BY f-QJV/ OmOzdO llllllllllllllllllllllllllllllllllll IIL ATTORNEYS March 29, 1949. M, WALLACE ET AL 2,465,500

MULTIBAND FIXED FREQUENCY CALIBRATION PANORAMIC RADIO RECEIVER Original Filed July 17,1941 2 Sheets-Sheet 2 INVENTORS MARCEL WALLACE HORACE G. MILLER NTL Patented Mar. 29, 1949 FIXED FREQUENCY CALIBRA- TION PANORAMIC RADIO RECEIVER Marcel Wallace, New York, N. Y., and Horace G.

Miller, Belleville, N.v J., assgnors, by mesne assignments, of one-half` to Marcel Wallace, doing business as* Panoramic Laboratories, New York, N. Y., and? one-halll to Panoramic Radio Corporation, Nevw York, N. Y., a corporation off N ew York',

Original application July 17, 1941, Serial, No. y 402,822'.A Divided' and this application December-1I, 1943, Serial` No. 513,894

14l Claims. (Cl` 250--20 This application is a. division of; our co-pend-- ing application Serial No. 402,822, led Julyl 1.7', 2941;, now Patent No. 2,381,940", which issued August; 14, 1945.

It also. related1- to: the patents or- Marcel' Wal'- lace Nos. 2,279,151 issuedf FebruaryA '7, 19:42',` 2f,-v 273,914` isued: February 24,1942', and' 2,312,203 is sued February 23, 1343, and' his co-pending application Serial No. 357.3814-, filed September 21', 1940, Inl said Wallace patents. and applications various: typesr` of panoramic. radio*A receivers using the single conversion superheterodyne principle have` been shown. These receivers contain gen-- orally a periodicallyA tunable element either driven a motor' or varied electronically and also a. manual tunable elementconnectedun the same tuning circuits for the manual tuning of the receiver over the' desired portion of the frequency spectrum.

Our patent application Serial No. 402,822 dis closes a panoramic receiver using the double conversion, superheterodyne principle.

This invention relates to improvements in methodsofpanoramic reception, and -toy methods. of' simultaneous'. aural and' panoramic reception'.-

Oneof the objects ofv our inventionA is to provide greater facility for manually tuning a. pan-.- oramic radio receiver overwl'de `frequency ranges while maintaining a substantially constant vis-- ual' band width.

Another object of) ourr invention isto provide means for simultaneous panoramicI receptionv ofA signals in two difierent bands;

Another object of' our invention is to provide means for the. simultaneous reception of signals two different bands combined with means. forr visualf observation of signals with the same resolution and? the' same iixed' frequency calibra tion over the screenfof the reciver; so thatl instantaneous determination of frequency differences' may be made.-

' Another object of' our invention is to 'prov-ide ilo'rI the simultaneous panoramic reception of sig-- nels over awi'de band and over` a narrow bandv contained? within the wide' band, the narrowA band providing a higher resolutionot the particular portion. ofthe bandit covers.

Another`- object. of our` invention is. to providefor the simultaneous panoramic: reception of signails in a wide band andv in a. narrow band contained within the wideband', on a single cathode ray screen, with i'lxed frequency calibration for eachband; In this casethe narrow band signals having a;A highere resolution will have one calibration scale and the wide band signals having a".

i lower resolution will. have a different calibration simultaneous reception of signals in two different bands, the selection of any signal in either band for aural: reception and the panoramic display of both bands simultaneously upon separate cathode ray tubes with the same xed frequency calibration for each band.

Figure 3 is a block diagram of apparatus for the simultaneous reception of a wide band and its panoramic diplay upon the screen of a cathode ray tube, the aural reception of any signal within said wide band, and the panoramic reception of any selected narrow band Within the wide band and its panoramic display upon a second cathode ray tube.

Figure 4 is a block diagram of the apparatus to the right of the broken line in Figure 3, showing an alternative means for the simultaneous panoramic display of a wide band of signals and of a narrow band within the wide band, with a single cathode rayv tube.

' Referring to Figure 1 for an explanation of the general principles involved in this invention, that figure shows in block diagram a tunable channel', an aural channel and a panoramic channel. The tunable, channell consists of a signal input, a first mixer, a first oscillator and a ganged' variable condenser. It is in essence simply the rst stage of a superheterodyne radio receiver, in which the antenna, first mixer, and iirst oscillator tube are each controlled by a variable con denser which condensers may be ganged for unicontrol. In the case of my tunable channel, however, the signal input circuit, which may include an RF-amplier containing one or several stages, and the coupling circuits of the rst mixer tube will' be designed to have a broad band pass characteristic so that instead of being tuned to receive a single broadcast signal, as they would in the case of the superheterodyne radio receiver,

they will be'broadly tunedr to receive a wide band oi-such signals.

The aural channel consists of a sharply tuned intermediate frequency amplifier which selects a single signal to which it is desired to listen, a detector and audio frequency amplifier, and an acoustic translating device, which is illustrated in the drawings as a pair of headphones.

The panoramic channel includes a second mixer tube, a second intermediate frequency amplifier, and a detector and audio frequency amplifier, the output of which supplies voltage to the vertical deilecting electrodes of a cathode ray tube. It also includes a source of sweep voltage for applying voltage to the horizontal deilecting electrodes of a cathode ray tube, a second oscillator supplying oscillations to the second mixer tube and a frequency control which periodically varies the tuning of the second oscillator over a band of frequencies in synchronism with the sweep voltage. The circuits in the panoramic channel will likewise be broadly tuned, but need not be so broadly tuned as those in the tunable channel. They may pass the entire band selected by the tunable channel or any selected portion thereof.

In the operation of the apparatus illustrated in Figure l, the tunable channel may be tuned to any selected band of frequencies. The aural intermediate frequency amplifier may be tuned to any signal within that band and this signal heard on the loud speaker or other accu-Stic translating device. The panoramic channel may receive all or any portion of the signals received in the tunable channel and display upon the face of the cathode ray tube a representation of a voltage corresponding to the amplitude of each signal within the band it receives.

If the panoramic channel is tuned to receive a band smaller than that of the tunable channel it may be tuned to any portion of the band of the tunable channel by varying the mid-frequency of the second oscillator by a manual tuning controlthe frequency control operating to vary these oscillations above and below the mid-frequency to an extent depending upon the width of the band to be observed on the screen of the cathode ray tube. The tunable channel may be varied by varying the ganged variable condensers to change the band being received, whereupon the oscillator in the panoramic channel may be tuned to select any signal within that band. The panoramic channel, if tuned to the same band width as the tunable channel, will then automatically display the new band. If, however, it is tuned to a smaller band width than the tunable channel, the midfrequency of the second oscillator may be varied to select any smaller band within the limits of the wide band.

It is to be observed that the frequency control of the panoramic channel varies the frequency of the second oscillator over the same frequency range above and below the mid-frequency at any setting. The panoramic display upon the screen of the cathode ray tube will, therefore, cover the same frequency spread regardless of the band being received. The screen may, therefore, be permanently calibrated in terms of frequency, and the frequency of any signal voltage displayed upon the screen read oil. by simply observing the frequency setting of the band being received and the position of the observed signal with respect to the center of the screen. This fixed frequency calibration is of considerable value in the use of panoramic receivers.

Figure 2 shows an application of the principles just described in connection with Figure 1, to the simultaneous panoramic reception of two Cil separate bands and their panoramic display upon two separate cathode ray tubes with the same fixed frequency calibration, and the simultaneous aural reception of any selected signal in either band. In Figure 2 there are two tunable channels each corresponding to the tunable channel of Figure 1. These may be tuned, for example, one to receive at a particular setting a band from to 130 megacycles and the other from 148 to 154 megacycles. Electronic switch No. 1, having two coupling tubes, provides for the signals in the two tunable channels to be alternately applied to a panoramic channel. A square wave generator alternately applies a blocking voltage to the grid of each coupling tube so that the signals from first one tunable channel and then the other are alternately applied to the panoramic channel. The outputs of the two tunable channels may have the same mid-frequency. The panoramic channel corresponds to the panoramic channel of Figure 1 so that its output will alternately be a signal voltage corresponding to the signals received in the two tunable channels. The square wave generator likewise applies a square wave blocking voltage alternately to two coupling tubes of electronic switch No. 2 both of which are coupled to the panoramic channel so that these tubes will alternately apply a signal voltage to the cathode ray tube to which it is connected. The sweep circuit of the panoramic channel supplies the same sweep voltage to each of the two cathode ray tubes shown, so that each of them will display panoramically the signals within one of the two tunable channels. A fixed frequency calibration may be applied to the screen oi' each tube as before, and the frequency of any signal corresponding to a representation appearing on the screen of a tube may, therefore. be read off directly, as before.

In our parent application, we have explained that a .panoramic receiver displaying a wide band will have a lower resolution than one displaying a narrow band, and that it is highly desirable for many applications to be able to observe a wide band and a-t the same time be able to select any portion of the wide band for observation with higher resolution.

Figure 3 illustrates how this may be done and simultaneously any signal within the wide band be received aurally. In Figure 3 there is a wide band tunable channel as before, and which may. of course, be manually tuned to vary the band received. This supplies two panoramic channels, each of which will correspond to the panoramic channel of Figure 1, and also supplies an aural channel, also corresponding to the aural channel of Figure 1, where any selected signal may be heard. In the wide band panoramic channel of Figure 3 the frequency variation of the second oscillator will be over a wide band and in the narrow band panoramic channel the frequency variation will be over a. narrower band, but the mld-frequency of the narrow `band oscillator will be variable so that the limits of the excursions of the oscillator may be varied to any frequency within the wide band of the iirst panoramic channel. The cathode ray screen displaying the wide band ypanoramic signals may cover, for example, a two megacycle band wi-th a resolution of 20 kilocycles, and lthe other screen a band of 100 kilocycles, `that is 5% of the first screen, with a. resolution of 4 kilocycles. What may appear as a Single signal on the rst screen may be resolved into a number of separate signals on the second 011e.

y It is to be observed, however, that the horizonsweep of both tubes in Figure 3 may have the same .form and frequency. That is the lsweep -yoltage applied to the two tubes maybe identical. It is, therefore, possible -to :combine the wide band and narrow -band signals on zthe screen of a vsingle vcathode ray tube as is illustrated in Figure 4. In this flgure the apparatus to the left ofthe broken line -of Figure 3 will be the same. Instead `of applying the signals from each pano- :amic channel :to a separate .cathode ray tube,

' however, as Iin Figure .3, Figure 4 illustrates a square wave generator which alternately applies lasquare wave blocking voltage to the grids of two coupling tubes, one coupled to each of the panoramictchannels vof Figure 3, and the outputs of .both connected to the vertical deec-ting elecof a single cathode ray tube. The `square wave generator likewise superimposes a square wave upon the signal voltage in one coupling tube so that the representation of the output ,of -one panoramic ,channel occurs along Ione horizontal axis of the cathode ray tube and that ofthe other channel upon another horizontal axis lvertically displaced from the first. .In this case the xed frequency calibration of the two representations will be different, but will remain constant with variations in the tuning of the tunable channel as well as of the wide band and the narrow band panoramic channels, so that aga-in the frequenci1 of Iany signal represented on the screen in either band may be read oif directly.

It will be understood that by the means illustrated and described in connection with Figure 4, the ltwocathode ray tubes shown in Figure 2 may be combined in a single tube with the signals from one tunable channel vertically displaced from the other tunablechannel.

Itwill be obvious to -those `skilled in the art that our invention is capable of various modifications and we, therefore, do not intend to be restricted except by the scope of the appended claims.

What is claimed is:

1. A panoramic receiver system .comprising two signal input channels individually tunable over different regions of the frequency spectrum, each of said channels including a frequency converting stage tunable to .a predetermined frequency, a panoramic receiving channel automatically and f periodically tuned over a portion of the frequency spectrum including said predetermined frequency, a square wave generating source operating in synchronism with .said periodic tuning, means operated in synchronism with said source for alternately coupling each of said input channels to said panoramic receiving channel, two display surfaces, and means for substantially simultaneously representing on said display surfaces each of the signals received through said two input channels.

l2. A receiving system as set forth in `claim 1 wherein each of the two input channels may be connected at will to an independent aural receiving channel.

3.`A panoramic receiving system including a signal receiving system, means for periodically tuning said signal receiving system over a predetermined portion of the frequency spectrum, means for converting each of the signals received over the said portion of the frequency spectrum into electric impulses, two visual display surfaces, means for representing in the form of visual signs on one of said display surfaces all of said electric impulses and on the other of the said display surfaces a. portion of said electric impulses, and

6 means operated Vin synchronism with said 'first means for separating said visual signs on yeach of said surfaces in accordance with the frequency separation between each of the corresponding signals.

ll. A panoramic receiving system including a signal receiving system, means .for periodically tuning said signal receiving system to cover two different bands of the frequency spectrum, means for converting each of the signals received in said two different bands into electric impulses, two visual display surfaces, means for representing in the form of visual ysigns on one of said display surfaces all of the electric impulses within one band and on the other display ysurface all the electric impulses within the other band, and means operated in synchronisin with said first means for separating the visual signs on each of said surfaces in accordance with the frequency separation between each of the corresponding signals.

5. A panoramic receiving system including a signal receiving system, means for periodically tuning said signal receiving system over a predetermined band of the frequency spectrum, means for converting each of the signals received over said band into electric impulses, two visual display surfaces, means for reproducing in the form of visual signs on one of said display surr faces a portion of the electric impulses within said band and on the other of said display surfaces a different portion of said electric impulses., means for varying the band of reception, and means for maintaining the separation of the visual signs of said surfaces in accordance with the frequency separation between each of the corresponding signals regardless of such variation inthe band received.

6. A panoramic receiving system comprising means for receiving a plurality of signals, means for varying the frequency band within which the signals are received, `means for converting each of the signals received into electric impulses, two visual display surfaces, means for representing in the form of visual signs on one of said display surfaces a portion of the received signals, means for representing in the form of visual signs on the other of said display surfaces another portion of said received signals, and means for .separating said visual signs on each of said surfaces in accordance with the frequency separation 'between each of the corresponding signals regardless of the variation of the band of received signals.

vv'7. A panoramic receiving system comprising two tunable channels,v means'for converting the signals received in said channels to the same frequency, a panoramic channel for converting said signals into .electrical impulses, means for alternately applying said signals to said panoramic channel, `a pair of display surfaces, means for representing saidelectrical impulses in the form of visual signs on said display surfaces, and means for alternately connecting said panoramic channel to said display surfaces whereby one of said display surfaces displays visual signs corresponding to signals received in one tunable channel and the other display surface displays signals received in the other tunable channel.

8. A panoramic receiving system comprising a tunable channel, a wide band panoramic channel connected to said tunable channel, a narrow band panoramic channel connected to said tunable cha-nnel, said narrow band being encompassed within said wide band, means comprising a, periodic tuning device within said wide band panoramic channel for converting said wide band of signal frequencies into electric impulses, means comprising a periodic tuning device within said narrow band panoramic channel for converting said narrow band of signals into electric impulses, a pair of display surfaces for representing electric impulses in the form of visual signs, and means comprising a sweep voltage synchronized with both said periodic tuning devices for representing the wide band electric impulses on one display surface and the narrow band electric impulses on the other display surface.

9. A panoramic receiving system comprising a tunable channel, a wide band panoramic channel coupled thereto for converting a wide band of signal frequencies into electrical impulses, a narrow band panoramic channel coupled to said tunable channel for converting a narrow band of signal frequencies into electrical impulses, a cathode ray screen, a pair of display surfaces on said screen, means for converting said electrical impulses into visual signs on said screen, and means whereby electrical impulses from said wide band and narrow band panoramic channels are alternately applied to said display surfaces.

l0. A panoramic receiver system comprising two signal input channels individually tunable over different regions of the frequency spectrum, each of said channels including a frequency converting stage tunable to a predetermined frequency, a panoramic receiving channel automatically and periodically tuned over a portion of the frequency spectrum including said predetermined frequency, a square-wave generating source operating in synchonism with said periodic tuning, means operated in synchonism with said source for alternately coupling each of said input channels to said panoramic receiving channel, and display surface means for substantially simultaneously representing on said display surface means each of the signals received through said two input channels.

11. A panoramic receiving system including a signal receiving system, means for periodically tuning said signal receiving system to cover two different bands of the frequency spectrum, means for converting each of the signals received in said two different bands into electric impulses, visual display surface means, means for representing in the form of visual signs on onev region of said display surface means all of the electric impulses within one band and on another region of said display surface means all the electric impulses within the other band, and means operated in synchronism with said tuning means for separating the visual signs on each of said surface regions in accordance with the frequency separation between each of the corresponding signals.

12. A panoramic radio receiving system including a signal receiving system, means for periodically tuning said signal receiving system over a predetermined band of the frequency spectrum, means for converting each of the signals received over said band into electric impulses, visual display surface means, means for reproducing in the form of visual signs on one region of said display surface means one portion of the electric impulses within said band and on another region of said display surface means a different portion oi' said electric impulses, means for varying ythe band of reception, and means for maintaining the separation of the visual signs on said surface regions in accordance with the frequency separation between each of the corresponding signals regardless of such variation in the band received.

13. A panoramic receiving system comprising two tunable channels, means for converting the signals received in said channels to the same frequency, a panoramic channel for converting said signals into electrical impulses, means for alternately applying said signals to said panoramic channel, display surface means, means for representing said electrical impulses in the form of visual signs on said display surface means and means for alternately connecting said panoramic channel to said display surface means whereby one region of said display surface means displays visual signs corresponding to signals received in one tunable channel and another region of the display surface means displays signals received in the other tunable channel. 14. A panoramic receiving system comprising a tunable channel, a wide band panoramic channel coupled thereto for converting a wide band of signal frequencies into electrical impulses, a narrow band panoramic channel coupled to said tunable channel for converting a, narrow band of signal frequencies into electrical impulses, cathode ray screen means having a pair of display surface regions, means for converting said electrical impulses into visual signs on said screenV means, and means whereby electrical impulses from said wide band and narrow band panoramic channels are alternately applied to said display surface regions.

MARCEL WALLACE. HORACE G. MILLER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,994,232 Schuck, Jr Mar. 12, 1935 2,063,610 Linsell Dec. 8, 1936 2,084,760 Beverage June 22, 1937 2,162,827 Schrader June 20, 1939 FOREIGN PATENTS Number Country Date 506,133 Great Britain s May 23, 1939 

